Impact modifier, thermoplastic resin composition using the same and molded article obtained therefrom

ABSTRACT

An impact modifier obtained by emulsion polymerizing acrylic monomer(s), etc., in the presence of a conjugated diene rubber to give a graft rubber polymer, or obtained by polymerizing acrylic monomer(s) and the like ethylenically unsaturated monomers in the presence of the graft rubber polymer, is effective for improving impact resistance and weathering resistance of molded articles obtained from thermoplastic resin compositions containing such an impact modifier.

BACKGROUND OF THE INVENTION

This invention relates to an impact modifier for thermoplastic resins, athermoplastic resin composition using the same, and an molded articleobtained therefrom.

Heretofore, in order to improve impact resistance of thermoplastic resincompositions, there have been compounded conjugated diene rubber graftcopolymers (e.g. MBS resin, ABS resin).

For example, vinyl chloride type resins are widely used for theiradvantages in flame retardancy, chemical resistance, etc. But the vinylchloride type resins have a defect in that the resins by themselves arepoor in impact resistance. Thus, the vinyl chloride type resins arecompounded with impact modifiers. But even if a methyl methacrylateresin, MBS resin or ABS resin is simply mixed with a commerciallyavailable vinyl chloride type resin, the resulting molded article is notsufficient in impact resistance due to poor dispersibility of individualcomponents.

In order to overcome this defect, it is proposed to use a graftcopolymer of conjugated diene rubber with a methyl methacrylatecopolymer obtained by suspension polymerization and having a suitablereduced viscosity (e.g. Japanese Patent Unexamined Publication Nos.60-161450 and 61-14246). But since such a conjugated diene rubbercomponent has many double bonds which are chemically unstable in themain chain, the graft copolymer is readily deteriorated by ultravioletrays, which results in making the outdoor practical use impossible dueto poor weathering resistance such as lowering in strength, causingdiscoloration, and the like.

In order to improve the weathering resistance, it is proposed to use amethyl methacrylate series polymer and a graft copolymer obtained bygrafting an acrylic acid alkyl ester, a methacrylic acid alkyl ester, anaromatic vinyl compound, a vinyl cyanide compound, and the like in thepresence of an acrylic rubber containing almost no double bonds in themain chain (Japanese Patent Unexamined Publication No. 59-98153). Butaccording to this proposal, the weathering resistance can be improved tosome extent, but there arises a problem of lowering impact resistance.

The methyl methacrylate series polymer used in the above proposal isexcellent in weathering resistance but is poor in flame retardancy,impact resistance, chemical resistance and solvent resistance. Thus,when the methyl methacrylate series polymer is mixed with a vinylchloride series resin, inherent properties of the vinyl chloride seriesresin are damaged.

As mentioned above, it was impossible to provide thermoplastic resincompositions well balanced in properties such as impact resistance,weathering resistance, etc.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an impact modifierfor thermoplastic resins such as vinyl chloride type resins forimparting excellent impact resistance and weathering resistance whilemaintaining inherent good properties such as flame retardancy, chemicalresistance, and the like. It is another object of the present inventionto provide a thermoplastic resin using such an impact modifier and amolded article obtained therefrom.

The present invention provides an impact modifier of a graft rubberpolymer (A) obtained by emulsion polymerizing

(a) 99 to 20 parts by weight of a polymerizable monomer mixturecomprising

(I) 0.1 to 20% by weight of a polyfunctional monomer,

(II) 50 to 99.9% by weight of an acrylic acid alkyl ester, the alkylmoiety thereof having 1 to 13 carbon atoms, and

(III) 0 to 30% by weight of a copolymerizable vinyl compound other thanthose mentioned above,

in the presence of

(b) 1 to 80 parts by weight of a conjugated diene rubber,

a total of the components (a) and (b) being 100 parts by weight.

The present invention also provides an impact modifier of a graftcopolymer (C) obtained by polymerizing

(B) 40% by weight or less and more than 0% by weight of one or moremonomers comprising

(IV) 0 to 100% by weight of an acrylic acid alkyl ester,

(V) 0 to 100% by weight of an aromatic vinyl compound,

(VI) 0 to 100% by weight of a methacrylic acid alkyl ester, and

(VII) 0 to 40% by weight of a vinyl cyanide compound,

in the presence of 60% by weight or more and less than 100% by weight ofthe graft rubber polymer (A) mentioned above.

The present invention further provides an impact modifier of a graftcopolymer (C) obtained by (i) emulsion polymerizing

(a) 99 to 20 parts by weight of a polymerizable monomer mixturecomprising

(I) 0.1 to 20% by weight of a polyfunctional monomer,

(II) 50 to 99.9% by weight of an acrylic acid alkyl ester, the alkylmoiety thereof having 1 to 13 carbon atoms, and

(III) 0 to 30% by weight of a copolymerizable vinyl compound other thanthose mentioned above,

in the presence of

(b) 1 to 80 parts by weight of a conjugated diene rubber,

a total of the components (a) and (b) being 100 parts by weight, to aconversion of 50 to 93% by weight to give a graft rubber polymer (A)containing unreacted polymerizable monomers, and (ii) polymerizing

(B) 40 parts by weight or less and more than 0 part by weight of one ormore monomers comprising

(IV) 0 to 100% by weight of an acrylic acid alkyl ester,

(V) 0 to 100% by weight of an aromatic vinyl compound,

(VI) 0 to 100% by weight of a methacrylic acid alkyl ester, and

(VII) 0 to 40% by weight of a vinyl cyanide compound,

in the presence of 60 parts by weight or more and less than 100 parts byweight of the graft rubber polymer (A), a total of the monomers (B) andthe graft rubber polymer (A) being 100 parts by weight (the impactmodifier of the graft copolymer (C) being particles having theconjugated diene rubber component as a nucleus and the acrylic rubbercomponent obtained from the component (a) as an outer shell, from theviewpoint of a structure).

The present invention still further provides a thermoplastic resincomposition comprising such an impact modifier and a thermoplasticresin.

The present invention also provides a molded article obtained by moldingsuch a thermoplastic resin composition.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an electron microscope photograph with magnification of 10,000of a OsO₄ stained ultrathin film sample showing a structure of a moldedarticle wherein one example of impact modifier particles of the presentinvention are dispersed in a matrix vinyl chloride resin.

FIG. 2 is an electron microscope photograph with magnification of 10,000of a RuO₄ stained ultrathin film sample showing the same structure asmentioned above.

FIG. 3 is an electron microscope photograph H with magnification of10,000 of a OsO₄.RuO₄ double stained ultrathin film sample showing thesame structure as mentioned above.

FIG. 4 is an electron microscope photograph with magnification of 40,000of a RuO₄ stained ultrathin film sample showing the same structure asmentioned above.

FIG. 5 is an electron microscope photograph with magnification of 10,000of a RuO₄ stained ultrathin film sample showing the structure of anotherexample of molded articles.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The impact modifier of graft rubber polymer (A) is explained below.

The graft rubber polymer (A) is obtained by using as a nucleus aconjugated diene rubber (b) having excellent properties as rubber andemulsion graft polymerizing thereonto an acrylic acid alkyl ester (II)and a polyfunctional monomer (I) as a crosslinking agent, each as anessential component. The graft rubber polymer (A) is effective forremarkably improving impact resistance.

As the conjugated diene rubber (b), there can be used polybutadiene, abutadiene-styrene copolymer, a butadiene-acrylonitrile copolymer, etc.

The polymerizable monomer mixture (a) comprises (I) a polyfunctionalmonomer, (II) an acrylic acid alkyl ester wherein the alkyl moiety has 1to 13 carbon atoms, and (III) a vinyl compound copolymerizable with thecomponents (I) and (II).

The polyfunctional monomer (I) is used in the polymerizable monomermixture (a) in an amount of 0.1 to 20% by weight, preferably 0.5 to 10%by weight, more preferably 1 to 5% by weight. When the amount is lessthan 0.1% by weight, the degree of crosslinking becomes insufficient,and impact resistance and surface appearance of molded articles becomepoor. On the other hand, when the amount is more than 20% by weight, thedegree of crosslinking becomes in excess and the impact resistance islowered.

As the polyfunctional monomer (I), there can be used divinyl benzene,dialkyl phthalate, triallyl isocyanurate, triallyl cyanurate,dicyclopentadiene acrylate, dicyclopentadiene methacrylate,1,3,5-triacryloylhexahydro-s-triazine, etc., alone or as a mixturethereof. The use of the first six compounds are particularly preferablefor providing excellent impact resistance and other properties.

As the acrylic acid alkyl ester (II) wherein the alkyl moiety thereofhaving 1 to 13 carbon atoms, there can be used methyl acrylate, ethylacrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexylacrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonylacrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, tridecylacrylate etc., alone or as a mixture thereof. Among them, the use ofbutyl acrylate is particularly preferable.

The acrylic acid alkyl ester (II) is used in the polymerizable monomermixture (a) in an amount of 50 to 99.9% by weight, preferably 65 to99.5% by weight. When the amount is less than 50% by weight, propertiesof the acrylic rubber is lowered, while when the amount is more than99.9% by weight, the impact resistance is lowered.

As the vinyl compound (III) copolymerizable with the polyfunctionalmonomer (I) and the acrylic acid alkyl ester (II), there can be usedacrylonitrile, methyl methacrylate, ethyl methacrylate,methacrylonitrile, styrene, etc., alone or as a mixture thereof.

The vinyl compound (III) is used in the polymerizable monomer mixture(a) in an amount of 0 to 30% by weight, preferably 0 to 25% by weight.When the amount is more than 30% by weight, properties as acrylic rubbercannot be obtained sufficiently by the polymerization of thepolymerizable monomer mixture (a).

The conjugated diene rubber (b) is used in an amount of 1 to 80 parts byweight, preferably 5 to 45 parts by weight, more preferably 20 to 45parts by weight, based on 100 parts by weight of the conjugated dienerubber (b) and the component (a) for obtaining the graft rubber polymer(A). When the amount is less than 1 part by weight, the impactresistance becomes insufficient. On the other hand, when the amount ismore than 80 parts by weight, weathering resistance is lowered.

For obtaining the graft rubber copolymer (A), it is preferable to usethe conjugated diene rubber (b) in the form of a latex obtained bypreviously dispersing it in an aqueous medium in order to make thedispersion easy at the time of emulsion polymerization. As the emulsionpolymerization method, there can be used conventionally used ones usingan emulsifier and a polymerization initiator.

As the emulsifier used in the emulsion polymerization for obtaining thegraft rubber polymer (A), there can be used anionic emulsifiers such assodium oleate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate,potassium oleate, etc.; nonionic emulsifiers such as polyoxyethylenemethyl ether, etc; rosined soap, etc.

The emulsifier is used preferably in an amount of 0.5 to 1.5% by weightbased on the total weight of the components (a) and (b).

As the polymerization initiator, there can be used conventionally usedones such as azo compounds e.g. 2,2'-azobisisobutyronitrile; persulfatese.g. potassium persulfate, ammonium persulfate, etc.; organic peroxidese.g. t-butyl peroxy maleic acid, cumene hydroperoxide, t-butylhydroperoxide, diisopropylbenzene hydroperoxide, p-menthanehydroperoxide, 1,1,3,3-tetramethyl butylhydroperoxide, etc.; inorganicperoxides e.g. hydrogen peroxide; and redox systems e.g. a peroxidementioned above/sodium formaldehyde sulfoxylate, a peroxide mentionedabove/sodium formaldehyde sulfoxylate/ferroussulfate/ethylenediaminetetraacetic acid.disodium salt, a peroxidementioned above/dextrose/sodium pyrophosphate/ferrous sulfate, etc. Thepolymerization initiator is used in an amount of preferably 0.02 to 5%by weight based on the weight of the component (a).

The graft rubber polymer (A) per se can be used as an impact modifier.In order to obtain more effective impact modifier, the graft rubberpolymer (A) is further used for polymerization to give the graftcopolymer (C). That is, the graft copolymer (C) is obtained bypolymerizing (B) one or more monomers comprising (IV) 0 to 100% byweight of an acrylic acid alkyl ester, (V) 0 to 100% by weight of anaromatic vinyl compound, (VI) 0 to 100% by weight of a methacrylic acidalkyl ester, and (VII) 0 to 40% by weight of a vinyl cyanide compound,the monomers (B) being in an amount of 40% by weight or less and morethan 0% by weight, in the presence of 60% by weight or more and lessthan 100% by weight of the graft rubber polymer (A).

More preferable graft copolymer (C) can be obtained by stopping thepolymerization of graft rubber polymer (A) before a conversion of 100%,preferably at a conversion of 50 to 93%, more preferably at a conversionof 60 to 90%, while retaining unreacted polymerizable monomers in thegraft rubber polymer (A), followed by mixing with one or more monomers(B) and polymerization.

The conversion can be determined by sampling a polymerization reactionsolution, adding a polymerization inhibitor thereto, removing a volatilecomponent using an infrared moisture meter, measuring the weight of anon-volatile component, and calculating the ratio of the weight ofnon-volatile component to the charging amounts of raw materials. Theunit of conversion is a percent by weight.

As the acrylic acid alkyl ester (IV), there can be used the same acrylicacid alkyl ester (II) having as the alkyl moiety 1 to 13 carbon atoms asmentioned above.

As the aromatic vinyl compound (V), there can be used styrene,α-substituted styrenes such as α-methyl styrene, α-ethyl styrene, etc.,substituted styrenes such as chlorostyrene, vinyltoluene,t-butylstyrene, etc.

As the vinyl cyanide compound (VII), there can be used acrylonitrile,methacrylonitrile, etc.

As the methacrylic acid alkyl ester (VI), there can be used methylmethacrylate, ethyl methacrylate, butyl methacrylate, etc.

As the monomer(s) (B), when the amount of the vinyl cyanide compound(VII) is too much, there is a tendency to lower moldability. Therefore,it is preferable to use the vinyl cyanide compound (VII) in an amount of40% by weight or less.

As the monomers (B), the use of methyl methacrylate, acrylonitrile andstyrene is preferable. Above all, the combined use of acrylonitrile andstyrene is particularly preferable from the viewpoint of balance ofimpact resistance and rigidity of molded articles. Acrylonitrile ispreferably used in an amount of 20 to 40 parts by weight, while styreneis used in an amount of 80 to 60 parts by weight, a total of the twobeing 100 parts by weight.

In the production of the graft copolymer (C), the graft rubber polymer(A) is used in an amount of 60% by weight or more and less than 100% byweight, preferably 99% by weight or less, and the monomers (B) are usedin amounts of 40% by weight or less and more than 0% by weight,preferably 1% by weight or more. When the weight ratio (A)/(B) is lessthan 60/40, the impact resistance is lowered, while when the weightratio is more than 99/1, there is a tendency to lower the impactresistance. On the other hand, when the compounding amount of the impactmodifier increases in order to compensate the lowering of impactresistance, inherent good properties of the matrix resin are damaged.

The polymerization of monomers (B) in the presence of the graft rubberpolymer (A) can be carried out either by polymerizing the whole amountsat one time, or by polymerizing in several times separately, or bypolymerizing the whole amounts while adding dropwise. A preferablemethod is to polymerize 5 to 30% by weight of the monomers (B) in thefirst stage, and to polymerize the rest of the monomers (B) in thesecond stage. The compositions of the monomers (B) to be addedseparately preferably contain not more than 40% by weight of the vinylcyanide compound. By employing the two-stage polymerization methodmentioned above, a resin having further higher impact resistance can beobtained.

The polymerization method for obtaining the graft copolymer (C) is notlimited to a special method and any conventional methods can be used.But considering the polymerization method for obtaining the graft rubberpolymer (A), an emulsion polymerization method is preferable.

The graft rubber polymer (A) and the graft copolymer (C) can becoagulated by using a salting-out method, filtered, and died to give thedesired impact modifiers, which are blended with other thermoplasticresins.

The obtained impact modifiers are in the form of particles having ashell-core structure wherein the diene rubber component imparting impactresistance forms a core, the acrylic rubber component obtained from thecomponent (a) imparting weathering resistance forms an outer shell, andif necessary, graft chains of a polymer of ethylenically unsaturatedmonomer(s) (B) imparting rigidity form a second outer shell. Therefore,there can be obtained very excellent impact resistance which has notbeen obtained by known impact modifiers.

As the thermoplastic resins to be blended with the impact modifiers ofthe present invention, there can be used conventional resins, forexample, vinyl chloride type resins such as polyvinyl chloride,polyvinyl chloride-containing resins, e.g. ethylene-vinyl chloridecopolymer, vinyl chloride-vinyl acetate copolymer, etc., poly(methylmethacrylate), polypropylene, polyethylene terephthalate, polybutyleneterephthalate, polycarbonate, polyamides such as polycaprolactam,polyhexamethylene adipate, etc., sytreneacrylonitrile copolymer resin,polyvinylidene dichloride, polyvinylidene fluoride, polyester carbonate,polysulfone, polyphenylene sulfide, etc.

Among them, the impact modifiers of the present invention are effectivefor improving impact resistance of vinyl chloride type resins containingthe vinyl chloride moiety in an amount of 80% by weight or more.

The compounding amount of the impact modifier in a thermoplastic resincomposition is usually 40 to 5% by weight, preferably 20 to 5% byweight, more preferably 15 to 6% by weight. When the amount of theimpact modifier is more than 40% by weight, there is a tendency to lowerinherent good properties of the thermoplastic resin to be blended and insuch a case, the impact modifier forms a continuous phase, resulting inrather lowering impact resistance. On the other hand, when the amount isless than 5% by weight, effects for improving the impact resistance andweathering resistance are lessened.

Blending of the impact modifier and a thermoplastic resin can be carriedout, for example, by mixing both powders using a Henschel-type mixer,followed by melt kneading.

As mentioned above, the impact modifiers of the present invention areparticularly useful for improving impact resistance and other propertiesof vinyl chloride type resins.

The vinyl chloride type resins include a homopolymer of vinyl chlorideand copolymers of vinyl chloride and other monomer(s) copolymerizabletherewith. Good properties can be obtained in the case of homopolymer ofvinyl chloride. In the case of copolymers of vinyl chloride, the contentof vinyl chloride of 80% by weight or more (copolymerizable monomercontent being 20% by weight or less) is preferable from the viewpointsof flame retardancy and fluidity. These homopolymer and copolymers canbe used alone or as a mixture thereof.

The monomer component copolymerizable with vinyl chloride includes, forexample, vinyl acetate, ethylene, propylene, etc. The use of vinylacetate, ethylene and/or propylene is preferable from the viewpoint offlame retardancy.

The vinyl chloride type resins can be produced by conventional methodssuch as suspension polymerization, emulsion polymerization, etc. It isalso possible to use commercially available vinyl chloride type resinssuch as Ryuron P.V.C. 7000, Ryuron P.V.C. 800 BL, Ryuron P.V.C. 800BK,Ryuron E-430, Ryuron E-650, Ryuron E-800, and Ryuron E-1050 (mfd. byTosoh Corp.), TK-700, TK-800, TK-1000, TK-1300, TK-1400, SG-400G,SC-500T, MA-800S, MC-700 (mfd. by Shin-Etsu Chemical Co., Ltd.), etc.

Vinyl chloride type resins having an average degree of polymerization of400 to 1300 according to JIS K-6721 are preferable from the viewpoint ofmolding. Further, the impact modifiers of the present invention are alsoeffective for vinyl chloride type resins having an average degree ofpolymerization of 1700 to 4500 and usually used by mixing with aplasticiser (semi-rigid and flexible polyvinyl chloride), andparticularly effective for improving impact resistance at lowtemperatures. In such a case, a plasticizer such as dioctyl adipate,dioctyl phthalate, or the like is used together.

A thermoplastic resin composition, e.g. a vinyl chloride type resincomposition, can be obtained by mixing a vinyl chloride type resin andan impact modifier of the present invention preferably in amountsmentioned above. The thermoplastic resin composition, e.g. the vinylchloride type resin composition may further contain one or more thermalstabilizers, light stabilizers, antioxidants, ultraviolet absorbers,lubricants, fillers, pigments, processing aids, plasticizers, etc.,depending on purposes. The kinds and amounts of these additives can beselected properly according to conventional methods.

The thermoplastic resin compositions such as vinyl chloride type resincompositions can be molded into sheets, plates, and the like moldedarticles by compression molding, injection, extrusion, casting,calendering, etc. Since the molded articles are excellent in weatheringresistance, they can be used as house-building parts and materials foroutdoor or indoor uses, furniture, containers, and the like.

The molded articles obtained from the thermoplastic resin compositionsof the present invention has a structure wherein particles of the impactmodifier are dispersed in the matrix thermoplastic resin, so that goodproperties are exhibited by such a structure.

The present invention is illustrated by way of the following Examples,in which all parts and percents are by weight, unless otherwisespecified.

EXAMPLE 1 (1) Production of Impact Modifier [Graft Rubber Polymer (A-1)]

In a 4-liter reactor equipped with a stirrer, 5.0 parts of potassiumoleate was dissolved in 240 parts of deionized water at 30° to 35° C.Then, 30 parts (solid weight) of butadiene rubber latex (SN-800 T, atrade name, mfd. by Sumitomo Naugatuck Co., Ltd.) was mixed therewith.Then, 1.4 parts of triallyl isocyanurate and 70 parts of butyl acrylatewere added to the reactor with stirring to give an emulsion. Dissolvedoxygen in the emulsion was replaced by nitrogen for about 1 hour withstirring until oxygen content became 2 ppm or less (measured by aUniversal Oxygen Analyzer, mfd. by Oriental Electric Co., Ltd.). Duringnitrogen replacement, there were prepared two containers, one of whichwere placed 0.04 part of potassium persulfate and 10 parts of deionizedwater and dissolved, and another of which were placed 0.004 part ofsodium sulfite and 10 parts of deionized water and dissolved. After thedissolved oxygen content in the emulsion became 2 ppm or less, theabove-mentioned two aqueous solutions were added to the emulsion,followed by temperature rise to 60° to 65° C. with stirring.

The polymerization was carried out at 60° to 65° C. for 3 to 4 hours.Then, the same aqueous solution of potassium persulfate as mentionedabove was added to the polymerization system, followed by 2 hours'polymerization at 85° to 90° C. until conversion of more than 95% tosubstantially complete the polymerization and to give a latex of graftcopolymer.

After cooling the latex, the latex was added dropwise to an aqueoussolution obtained by dissolving 10 parts of potassium alum in 500 partsof deionized water for salting-out, followed by filtering and drying togive a powder of graft rubber polymer (A-1).

(2) Production of Vinyl Chloride Resin Composition

Vinyl chloride-ethylene copolymer having an average degree ofpolymerization of 650 (Ryuron E-650, a trade name, mfd. by Tosoh Corp.)in an amount of 90 parts, 10 parts of the graft rubber polymer (A-1)obtained in above (1) as an impact modifier, 3 parts of dibutyl tinmaleate as a stabilizer, and 2 parts of calcium stearate melt kneaded ina single screw extruder having a diameter of 40 mm (mfd. byThermoplastic Industry Co., Ltd.) to give pellets. The cylinder and dicetemperatures of the extruder were in the range of 150° to 180° C.

(3) Evaluation Method

The pellets produced in above (2) were injection molded into test piecesfor test using an in-line screw type injection molding machine (SJ-25/35type, mfd. by Meiki Co., Ltd.) with a cylinder temperature of 180° to190° C. and a mold temperature of 50° to 55° C. The test pieces weresubjected to measurements of Izod impact strength and weatheringresistance.

The results are shown in Table 1.

Weathering resistance was measured using a sunshine weather meter byaccelerated weathering test according to JIS A1415 and evaluated by acolor difference ΔE after 1000 hours according to JIS A1411.

Izod impact strength was measured according to ASTM D256.

As is clear from Table 1, the molded article obtained in Example 1showed Izod impact strength of 957 J/m at 23° C. and ΔE of 5 to 7. Thus,impact resistance and weathering resistance were excellent.

EXAMPLES 2 TO 4

Using the graft rubber polymer (A-1) produced in Example 1 as an impactmodifier, vinyl chloride resin compositions were prepared with mixingamounts shown in Table 1. Test pieces were molded and subjected to thetests in the same manner as described in Example 1. The results areshown in Table 1.

EXAMPLES 5 AND 6

Graft rubber polymer (A-2) was prepared in the same manner as describedin Example 1 except for using the butadiene latex in an amount of 40parts in place of 30 parts and butyl acrylate in an amount of 60 partsin place of 70 parts. Using the graft rubber polymer (A-2), vinylchloride resin compositions were prepared with the mixing ratios asshown in Table 1.

Test pieces for measuring were prepared and subjected to evaluation ofimpact resistance and weathering resistance in the same manner asdescribed in Example 1. The results are shown in Table 1.

EXAMPLES 7 AND 8

Graft rubber polymer (A-3) was prepared in the same manner as describedin Example 1 except for using the butadiene latex in an amount of 20parts in place of 30 parts and butyl acrylate in an amount of 80 partsin place of 70 parts. Using the graft rubber polymer (A-3), vinylchloride resin compositions were prepared with the mixing ratios asshown in Table 1.

Test pieces for measuring were prepared and subjected to evaluation ofimpact resistance and weathering resistance in the same manner asdescribed in Example 1. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1

Test pieces were prepared in the same manner as described in Example 1except for not using the graft rubber polymer (A-1) (i.e. using onlyRyuron E-650). Impact resistance and weathering resistance were measuredin the same manner as described in Example 1. The results are shown inTable 1.

As shown in Table 1, Izod impact strength is 38 J/m at 23° C. and ΔE is30 or more. This means that the molded article of vinyl chloride resinalone is considerably inferior in impact resistance and weatheringresistance to those of vinyl chloride resin compositions mixed with agraft rubber polymer (A).

EXAMPLE 9

Test pieces were prepared by using a vinyl chloride resin composition aslisted in Table 1 containing the graft rubber polymer (A-1) obtained inExample 1. Impact resistance and weathering resistance were measured inthe same manner as described in Example 1. The results are shown inTable 1.

As shown in Table 1, Izod impact strength is 187 J/m at 23° C. and ΔE is9 to 11. This means that when the proportion of the graft rubber polymerincreases, there is a tendency to lower impact resistance due toformation of a continuous phase.

COMPARATIVE EXAMPLES 2 AND 3

Rubber containing butyl acrylate as a major component was produced inthe same manner as described in Example 1 except for not using thebutadiene rubber. Vinyl chloride resin compositions were prepared byusing the resulting rubber in place of the graft rubber polymer (A) inthe same manner as described in Example 1.

Test pieces were prepared and subjected to evaluation of impactresistance and weathering resistance in the same manner as described inExample 1. The results are shown in Table 1.

As is clear from Table 1, when the butyl acrylate rubber is used inplace of the graft rubber polymer (A), the weathering resistance isalmost the same (ΔE being 8 to 10), but Izod impact strength (170 J/m orless) is poor.

COMPARATIVE EXAMPLES 4 AND 5

Butadiene rubber (SN-800T, mfd. by Sumitomo Naugatuck Co., ltd.) wasused in place of the graft rubber polymer (A) to give vinyl chlorideresin compositions. Impact resistance and weathering resistance weremeasured in the same manner as described in Example 1 and listed inTable 1.

As is clear from Table 1, the Izod impact strength is as considerablylow as about 40 J/m. This seems to be derived from incompatibilitybetween the butadiene rubber and vinyl chloride resin. Further, theweathering resistance (ΔE=30 or more) is considerably poor.

                  TABLE 1    ______________________________________           Vinyl chloride           resin composition             Vinyl chlo-                       Impact             ride resin                       modifier   Izod             (Ryuron   (Graft rubber                                  impact Weathering    Example  E-650)    polymer (A))                                  strength                                         resistance    No.      (parts)   (parts)    (J/m)  ΔE    ______________________________________    Example 1             90        A-1  10    957    5˜7    Example 2             80        A-1  20    1205   5˜7    Example 3             60        A-1  40    962    7˜8    Example 4             95        A-1   5    273    7˜8    Example 5             90        A-2  10    705    7˜9    Example 6             80        A-2  20    950     8˜10    Example 7             90        A-3  10    836    5˜7    Example 8             80        A-3  20    1037   5˜7    Example 9             50        A-1  50    187     9˜11    Comparative             100             0     38    30 or more    Example 1    Comparative             90             10    111     8˜10    Example 2    Comparative             80             20    162     8˜10    Example 3    Comparative             90             10     39    30 or more    Example 4    Comparative             80              20    42    30 or more    Example 5    ______________________________________

EXAMPLES 10 TO 12, COMPARATIVE EXAMPLE 6 (1) Production of Graft RubberPolymer Latex (A)

In a 4-liter reactor equipped with a stirrer, 1324 g of butadiene rubberlatex (solid content 34%, UB-1001S, mfd. by Nippon Zeon Co., Ltd.) and11.6 g of semi-hardened tallow fatty acid potassium salt (KS Soap, mfd.by Kao Corp.) dissolved in 1060 g of deionized water, 1050 g of butylacrylate and 21 g of triallyl isocyanurate were placed and mixeduniformly to give an emulsion. Nitrogen was introduced into the emulsionwith stirring for about 1.5 hours until the dissolved oxygen contentbecame 2 ppm or less. After adding an aqueous solution dissolving 0.5 gof potassium persulfate in 50 g of pure water and an aqueous solutiondissolving 0.5 g of sodium sulfite in 50 g of pure water to theemulsion, the temperature was raised to 60° C. The polymerization wascarried out at 60° C. for 4.5 hours to substantially complete thepolymerization at the conversion of 98% and to give a graft rubberpolymer latex (A).

(2) Production of Graft Copolymer (C-1)

In a 4-liter flask equipped with a stirrer, 2332 g of the graft rubberpolymer latex (A) obtained in above (1) (solid content 42%), 20.2 g ofacrylonitrile, 40.8 g of styrene, 0.22 g of cumene hydroperoxide, 1.2 gof sodium lauryl sulfate (Emal 2F, mfd. by Kao Corp.), 6.0 g ofsemi-hardened tallow fatty acid potassium salt (KS Soap, mfd. by KaoCorp.) and 340 g of pure water were placed and mixed uniformly. Afterintroducing nitrogen into the emulsion for about 1.5 hours until thedissolved oxygen content became 2 ppm or less, 1.0 g of sodiumformaldehyde sulfoxylate (Rongalite SFS, mfd. by Sumitomo Chemical Co.,Ltd.) and 60 g of pure water were added thereto and the temperature wasraised to 65° C. After 1.5 hours while maintaining the temperature at65° C., 5.1 g of potassium carbonate and 100 g of pure water were added,followed by dropwise addition of uniformly mixed solution of 4.2 g of KSSoap, 23.5 g of deionized water, 51.9 g of acrylonitrile, 120 g ofstyrene, 0.6 g of cumene hydroperoxide and 0.65 g of t-dodecylmercaptane for about 1.5 hours. After the dropwise addition, stirringwas continued for about 3 hours. Then, an aqueous solution of potassiumpersulfate (KPS) was added and the polymerization was carried out at 75°C. for about 1 hour to give a graft copolymer latex with a conversion of97% or more. After cooling to room temperature, an aqueous solution ofpolyvinyl alcohol was added to the graft copolymer latex with stirringfor demulsifying. After repeating dehydration and washing, and drying, apowder of impact modifier was obtained.

(3) Production of Vinyl Chloride Resin Composition

To 100 parts of vinyl chloride resin having an average degree ofpolymerization of 1050 (homopolymer of vinyl chloride, TK-1000, mfd. byShin-Etsu Chemical Co., Ltd.), the impact modifier obtained above inamounts as shown in Table 2, 3 parts of dibutyl tin maleate as astabilizer and a mixture of 1 part of polyethylene wax and 0.5 part ofcalcium stearate were added and roll kneaded at 170° C., followed bypress molding at 190° C. to give test pieces.

Various tests were carried out and listed in Table 2.

                  TABLE 2    ______________________________________             Comparative                      Example    Example No.               Example 6  10       11     12    ______________________________________    Amount of impact               0          6        8      10    modifier (parts)    Izod impact               46         350      1090   1130    strength (J/m)    Tensile    54         50       40     43    strength *1 (MPa)    Flexural   2760       2500     2300   2180    modulus *2 (MPa)    Vicat      92.8       93.3     93.9   95.2    softening *3    temperature (°C.)    ______________________________________     Note)     *1: JIS K7113     *2: ASTM D790     *3: JIS K7206

EXAMPLES 13 TO 15, COMPARATIVE EXAMPLE 7

To 100 parts of vinyl chloride resin having an average degree ofpolymerization of 800 (homopolymer of vinyl chloride, TK-800, mfd. byShin-Etsu Chemical Co., Ltd.), the impact modifier obtained in Example10 in amounts as shown in Table 3, 1 part of tribasic lead sulfate, 0.5part of dibasic lead stearate, 2 parts of lead stearate, 0.3 part ofbarium stearate, and 0.2 part of calcium stearate were added, meltkneaded at 170° C., and press molded at 190° C. to give test pieces fromresin plates.

Properties were evaluated in the same manner as described in Example 10.The results are shown in Table 3.

                  TABLE 3    ______________________________________             Comparative                      Example    Example No.               Example 7  13       14     15    ______________________________________    Amount of impact               0          6        8      10    modifier (parts)    Izod impact               86         420      1060   1080    strength (J/m)    Tensile strength               54         45       44     43    (MPa)    Flexural modulus               2770       2310     2290   2260    (MPa)    Vicat softening               95.0       92.8     92.9   92.3    temperature (°C.)    ______________________________________

EXAMPLE 16 (1) Production of Graft Rubber Polymer Latex (A)

In a 4-liter reactor equipped with a stirrer, the following butadienerubber latex 1, emulsifier 2 and monomers 3 were placed and mixeduniformly to give an emulsion. After making the dissolved oxygen contentin the emulsion 2 ppm or less by introducing nitrogen thereinto forabout 1.5 hours, the following polymerization initiator 4 and auxiliary5 were added and the temperature was raised to 60° C. After about 1.5hours while maintaining the temperature at 60° C., the same aqueoussolution of potassium persulfate as the component 4 was added theretoand the polymerization was carried out at 60° C. for further 3 hours.When the conversion became more than 95%, the polymerization wascompleted substantially to give a graft rubber polymer latex (A).

    ______________________________________    Component 1  Butadiene rubber latex                                    1324 g                 (UB-1001S, mfd. by Nippon                 Zeon Co., Ltd., solid content                 34%)    Component 2  Semi-hardened tallow                                    11.6 g                 fatty acid potassium salt                 (KS Soap, mfd. by Kao Corp.)                 Pure water         1060 g    Component 3  Butyl acrylate     1050 g                 Trially isocyanurate                                    21 g    Component 4  Potassium persulfate                                    0.5 g                 Pure water         50 g    Component 5  Sodium sulfite     0.13 g                 Pure water         50 g    ______________________________________

(2) Production of Graft Polymer (C)

In a 4-liter flask equipped with a stirrer, the graft rubber polymerlatex 1 (solid content 40%) obtained in above (1), the followingemulsifier 2 and grafting component (monomers) 3 were placed and mixeduniformly to give an emulsion. After making the dissolved oxygen contentin the emulsion 2 ppm or less by introducing nitrogen thereinto forabout 1.5 hours, the following polymerization initiating auxiliary 4 wasadded thereto, and the temperature was raised to 65° C. After 1.5 hourswhile maintaining the temperature at 65° C., the following component 5was added, followed by dropwise addition of a uniformly emulsified mixedsolution of the following component 6 and component 7 in about 1.5 hoursAfter the dropwise addition, stirring was continued for further 3 hours,followed by addition of the following component 8. After polymerizing at75° C. for 1 hour, the polymerization was substantially completed at aconversion of 97% or more to give a graft copolymer latex (C). Aftercooling to room temperature, an aqueous solution of polyvinyl alcoholwas added to the graft copolymer latex with stirring for demulsifying.After repeating dehydration and washing, and drying, there was obtaineda powder of impact modifier (graft copolymer).

    ______________________________________    Component 1  Graft rubber polymer latex                                    2700 g    Component 2  Sodium lauryl sulfate                                    1.2 g                 Potassium oleate   6.0 g                 Pure water         340 g    Component 3  Acrylonitrile      10.1 g                 Styrene            20.4 g                 Cumene hydroperoxide                                    0.11 g    Component 4  Sodium formaldehyde                                    1.03 g                 sulfoxylate                 Pure water         60 g    Component 5  Potassium carbonate                                    5.26 g                 Pure water         100 g    Component 6  Potassium oleate   2.1 g                 Pure water         117.5 g    Component 7  Acrylonitrile      26.0 g                 Styrene            60.0 g                 Cumene hydroperoxide                                    0.30 g                 t-Dodecyl mercaptan                                    0.33 g    Component 8  Potassium persulfate                                    2.5 g                 Pure water         100 g    ______________________________________

The resulting impact modifier in an amount of 8 parts was mixed with 100parts of vinyl chloride homopolymer having an average degree ofpolymerization of 1050 (TK-1000, mfd. by Shin-Etsu Chemical Co., Ltd.),followed by melt kneading with a mixture comprising 1 part of tribasiclead sulfate, 0.5 part of dibasic lead stearate, 2 parts of leadstearate, 0.3 part of barium stearate and 0.2 part of calcium stearate.A resin plate was obtained by press molding at 190° C., and subjected toIzod impact test. The Izod impact strength (notched) was 1080 J/m, whichvalue was remarkably high compared with the value of 86 J/m containingno impact modifier.

EXAMPLE 17

A graft copolymer latex was obtained in the same manner as described inExample 16 (2) except for using the following components 1, 3, 6 and 7.

    ______________________________________    Component 1  Graft rubber polymer latex                                    1748 g    Component 3  Acrylonitrile      40.4 g                 Styrene            81.6 g                 Cumene hydroperoxide                                    0.43 g    Component 6  Potassium oleate   8.3 g                 Pure water         470 g    Component 7  Acrylonitrile      103.7 g                 Styrene            240.1 g                 Cumene hydroperoxide                                    1.2 g                 t-Dodecyl mercaptan                                    1.31 g    ______________________________________

The resulting latex was subjected to demulsification, followed bydehydration, washing and drying to give a powder of impact modifier.

The obtained impact modifier in an amount of 15 parts was added to 100parts of homopolymer of vinyl chloride having an average degree ofpolymerization of 1050 (TK-1000, mfd. by Shin-Etsu Chemical Co., Ltd.),followed by melt mixing with a mixture comprising 3 parts of dibutyl tinmaleate as a stabilizer, 0.5 parts of calcium stearate and 0.5 part ofstearyl stearate in the same manner as described in Example 16(2). Atest piece was obtained by press molding. The Izod impact strength(notched) was 780 J/m.

EXAMPLE 18

The impact modifier obtained in Example 10(2) in an amount of 10 partswas added to 100 parts of poly(methyl methacrylate) (Parapet G, a tradename, mfd. by Kyowa Gas Chemical Industry Co., Ltd.) and melt kneaded at190° C. , followed by press molding at 200° C. to give a resin plate.Test pieces were cut from the resin plate and subjected to impactstrength test (notched). The Izod impact strength (notched) was 75 J/m,which value was higher than the value of 30 J/m when no impact modifierwas added.

EXAMPLE 19

The impact modifier obtained in Example 10(2) in an amount of 15 partswas added to 100 parts of polycarbonate resin (Iupilon S-100, a tradename, mfd. by Mitsubishi Gas Chemical Co., Inc.) and melt kneaded at250° C., followed by press molding at 240° C. The Izod impact strength(notched) was 560 J/m, which value was higher than the value of 300 J/mwhen no impact modifier was added.

EXAMPLE 20

The impact modifier obtained in Example 10(2) in an amount of 15 partswas added to 100 parts of polypropylene (Hipol J800, a trade name, mfd.by Mitsui Petrochemical Industries, Ltd.) and melt kneaded at 180° C.,followed by press molding at 190° C. The Izod impact strength (notched)was 50 J/m, which value was higher than the value of 20 J/m when noimpact modifier was added.

COMPARATIVE EXAMPLE 8

A graft copolymer latex was prepared in the same manner as described inExample 16(2) except for using the following components 1, 3, 6 and 7.

    ______________________________________    Component 1  Graft rubber polymer latex                                    1500 g    Component 3  Acrylonitrile      50.5 g                 Styrene            102.0 g                 Cumene hydroperoxide                                    0.55 g    Component 6  Potassium oleate   10.5 g                 Pure water         587.5 g    Component 7  Acrylonitrile      129.8 g                 Styrene            300 g                 Cumene hydroperoxide                                    1.5 g                 t-Dodecyl mercaptan                                    1.63 g    ______________________________________

The resulting latex was subjected to demulsification, followed bydehydration, washing, and drying to give a powder of impact modifier.

Using the resulting impact modifier, the Izod impact test was carriedout in the same manner as described in Example 16(2). The Izod impactstrength (notched) was 98 J/m.

EXAMPLE 21

The impact modifier obtained in Example 10(2) in an amount of 15 partswas added to 100 parts of polybutylene terephthalate (Teijin PBT, C7000,mfd. by Teijin, Ltd.) and melt kneaded at 240° C., followed by pressmolding. The Izod impact strength (notched) was 500 J/m, which value wasremarkably higher than the value of 45 J/m when no impact modifier wasadded.

EXAMPLE 22

An injection molded article obtained from the vinyl chloride resincomposition obtained in Example 1 was cut to give ultrathin films andeach cross-section was stained to examine particle structures. Stainingwas carried out by OsO₄ staining (FIG. 1), RuO₄ staining (FIGS. 2 and4), and OsO₄.RuO₄ double staining (FIG. 3) according to the methodsdescribed in "Zairyo (Materials)" vol. 19, No. 197, pp 77-83 (1970) and"Macromolecules" 1983, vol. 16, pp. 589-598. The stained ultrathin filmswere subjected to observation for phase separation structures using atransmission type electron microscope (H-600 type, mfd. by Hitachi,Ltd.) at an accelerated voltage of 100 KV.

As is clear from FIGS. 1 to 4, composites comprising OsO₄ stainableparticles having a particle size of about 0.1 to 0.5 μm, that is, nucleamade from butadiene rubber, and outer shells made from RuO₄ dyeablecomponent, that is, butyl acrylate rubber, are dispersed in the matrixvinyl chloride type resin.

EXAMPLE 23

A press molded article obtained from the vinyl chloride resincomposition obtained in Example 11 was cut to give ultrathin films andeach cross-section was RuO₄ stained in the same manner as described inExample 22. The phase separation structure was observed using thetransmission type electron microscope (H-600 type, mfd. by Hitachi,Ltd.) and shown in FIG. 5.

As is clear from FIG. 5, composites comprising not-RuO₄ stainedparticles, i.e. butadiene rubber component covered with RuO₄ stainablecomponent, i.e., acrylic rubber, are dispersed in the matrix vinylchloride resin.

EXAMPLE 24 (1) Production of Graft Copolymer (C-1)

In a 4-liter reactor equipped with a stirrer, 1.0 part of potassiumoleate was dissolved in 240 parts of deionized water at 30° to 35° C.with stirring. Then, 30 parts (as solid content) of polybutadiene rubberlatex (SN-800T, a trade name, mfd. by Sumitomo Naugatuck Co., Ltd.), 1.4part of triallyl isocyanurate and 70 parts of butyl acrylate were placedin the reactor to give an emulsion. The dissolved oxygen content in theemulsion was made 2 ppm or less (measured by a Polaro type DO meter RA,mfd. by Oriental Electric Co., Ltd.) by introducing nitrogen into theemulsion for about 1 hour. During that period, an aqueous solutionobtained by dissolving 0.04 part of potassium persulfate in 10 parts ofdeionized water and an aqueous solution obtained by dissolving 0.004part of sodium sulfite in 10 parts of deionized water were prepared,respectively. After making the dissolved oxygen content in the emulsion2 ppm or less, the two aqueous solutions mentioned above were added tothe emulsion and the temperature was raised to 60° to 65° C. whilecontinuing the nitrogen replacement. After polymerizing for about 3hours, the resulting emulsion was cooled. The conversion was 85%. Thiswas named as graft rubber polymer (A).

Then, the following seven components were prepared.

    ______________________________________    Component (1):    Sodium lauryl sulfate   1.2    parts    Potassium oleate        5.0    parts    Deionized water         240    parts    Component (2):    Cumene hydroperoxide    0.2    part    Acrylonitrile           17.2   parts    Styrene                 35.0   parts    Component (3):    Sodium formaldehyde sulfoxylate                            0.90   part    Deionized water         60     parts    Component (4):    Potassium carbonate     4.4    parts    Deionized water         120    parts    Component (5):    Potassium leate         3.7    parts    Deionized water         200    parts    Component (6):    Cumene hydroperoxide    0.51   part    t-Dodecyl mercaptan     0.56   part    Acrylonitrile           44.4   parts    Styrene                 103.4  parts    Component (7):    Potassium persulfate    2.4    parts    Deionized water         120    parts    ______________________________________

In a 4-liter reactor equipped with a stirrer, 800 parts (as solidcontent) of the graft rubber polymer (A) obtained above and thecomponent (1) were placed and mixed uniformly. Then, the component (2)was added thereto with stirring to give an emulsion and the stirring wascontinued. After making the dissolved oxygen content in the emulsion 2ppm or less by introducing nitrogen thereinto for about 1 hour, thecomponent (3) was added thereto. The temperature was raised to 65° C.and polymerization was carried out at that temperature for about 1 hour(until conversion of about 70%). Then, a uniformly mixed solution of thecomponents (4), (5) and (6) was added to the reactor dropwise in about 2hours. Then, the reaction was continued for about 5 hours until theconversion became 80 to 85%. Then, the component (7) was added and thepolymerization temperature was raised to 80° C. The polymerization wascarried out at that temperature for about 2 hours to give a graftcopolymer latex (C-1) having a conversion of 97% or more, followed byfiltration, washing and drying.

(2) Production of Vinyl Chloride Type Resin Composition

To 90 parts of vinyl chloride type resin (D) having an average degree ofpolymerization 650 (copolymer of vinyl chloride and ethylene, RyuronE-650, mfd. by Tosoh Corp.), a mixture of 10 parts of the graftcopolymer (C-1) obtained in above (1), 3 parts of dibutyl tin maleate asa stabilizer (KS-1B, mfd. by Kyodo Chemical Co., Ltd.), 1 part ofcalcium stearate, and 0.5 part of stearyl stearate was added and meltkneaded in a single screw extruder having a diameter of 40 mm (mfd. byThermoplastic Industry Co., Ltd.) to give pellets. Both the cylinder anddie temperatures of the extruder were in the range of 150° to 180° C.

(3) Evaluation

Test pieces for measuring were obtained by injection molding using thepellets prepared in above (2) and an in-line screw type injectionmolding machine (SJ-25/35 type, mfd. by Meiki Co., Ltd.) at a cylindertemperature of 180° to 190° C. and a mold temperature of 50° to 55° C.

Various properties were measured according to JIS or ASTM standards.

Weathering resistance was measured using a sunshine weather meter by anaccelerated weathering test (JIS A1415) and evaluated by the colordifference ΔE after 1000 hours according to JIS A1411.

The Izod impact strength (V notched) was 1000 J/m at 23° C., and nodestruction was caused by Izod impact test (no notch) at -10° C. and-30° C.

In the Du Pont type falling weight impact test (ASTM D2794-69) usingtest pieces of 2 mm thick, there were obtained 10.3 J at 23° C., 5.9 Jat -10° C. and 4.9 J at -30° C.

Further, ΔE, which is a measure of weathering resistance, was 4-6 toshow good weathering resistance.

EXAMPLES 25 AND 29

Using the graft copolymer (C-1) obtained in Example 24, vinyl chloridetype resin compositions as shown in Table 4 were prepared and evaluatedin the same manner as described in Example 24. The results are shown inTable 4.

EXAMPLES 26 TO 28

Using graft rubber polymers (A) in the course of producing the graftcopolymer in Example 24, graft copolymers (C-2), (C-3) and (C-4) wereproduced by changing the monomers of the components (2) and (6) to othermonomers but in the same manner as described in Example 24. In the caseof (C-2), the same amount of methyl methacrylate was used in place ofstyrene. In the case of (C-3), the same amount as a total of methylmethacrylate was used in place of styrene and acrylonitrile. In the caseof (C-4), the same amount of a mixture of styrene and α-methyl styrene(2:5 in weight ratio) was used in place of styrene. Using these graftcopolymers, vinyl chloride type resin compositions as shown in Table 4were produced and evaluated in the same manner as described in Example24. The results are shown in Table 4.

COMPARATIVE EXAMPLE 9

Using 100 parts of the same vinyl chloride type resin alone as used inExample 24 without adding the graft copolymer thereto, the propertieswere evaluated in the same manner as described in Example 24.

The Izod impact strength (V notched) was 40 J/m at 23° C. The Izodimpact strength (no notch) was 30 J/m at -10° C., and impossible tomeasure (under the lower limit of measurable values) at -30° C.

The Du Pont type falling weight impact strength was as low as 0.44 J at23° C., 0.15 J at -10° C. and impossible to measure at -30° C.

The ΔE was 30 or more and deterioration in weathering resistance wasremarkable.

As a result, the vinyl chloride type resin alone was inferior in impactresistance and weathering resistance to the compositions compounded withthe graft copolymers.

The results are also shown in Table 4.

EXAMPLE 30

Using the graft copolymer (C-1) produced in Example 24, a vinyl chloridetype resin composition as shown in Table 4 was produced and evaluated.

The Izod impact strength (V notched) was 187 J/m at 23° C., and the Izodimpact strength (no notch) was 670 J/m at -10° C. and 340 J/m at -30° C.

The Du Pont type falling weight impact strength was 8.8 J at 23° C., and4.9 J at -10° C. and -30° C.

The ΔE, which is a measure of weathering resistance, was 9-11 andexcellent in the weathering resistance.

But with an increase of the graft copolymer component, the continuousphase is formed to lower the impact resistance.

The results are also shown in Table 4.

COMPARATIVE EXAMPLES 10 TO 12

Acrylic rubber polymers were produced without using butadiene rubber inthe same manner as described in Example 24 for producing the graftcopolymer. Using this, a graft copolymer (C-5) was produced. Using thegraft copolymer (C-5), vinyl chloride type resin compositions as shownin Table 4 were produced and evaluated in the same manner as describedin Example 24.

A resin composition using the graft copolymer (C-5) produced in thepresence of acrylic rubber obtained by using only butyl acrylate havingno nucleus of butadiene rubber shows poor Izod impact strength of 370J/m at 23° C. (1000 J/m in Example 24 containing butadiene rubber as anucleus). As to the weathering resistance, ΔE is 8-10, which is the sameas Example 24.

The results are also shown in Table 4.

COMPARATIVE EXAMPLES 13 TO 15

A graft copolymer (C-6) was produced by using 800 parts of onlybutadiene rubber (SN-800T) in place of the graft copolymer (A) used inExample 24. Using this graft copolymer, vinyl chloride type resincompositions as shown in Table 4 were produced and evaluated in the samemanner as described in Example 24.

A resin composition using the graft copolymer (C-6) produced in thepresence of only butadiene rubber shows poor Izod impact strength of 560J/m at 23° C. (1000 J/m in Example 24 using also acrylic rubber).Further, ΔE is more than 30 and the weathering resistance isconsiderably poor. The results are also shown in Table 4.

                                      TABLE 4    __________________________________________________________________________                         Example    Example No.          24    25    26    27    28    29    30    __________________________________________________________________________    Vinyl     Vinyl chloride type                          90    91    90    90    90    80    30    chloride  resin (parts)    type resin              Graft C-1   10    9    --    --    --     20    50    composition              copolymer                    C-2  --    --     10   --    --    --    --              (parts)                    C-3  --    --    --     10   --    --    --                    C-4  --    --    --    --     10   --    --                    C-5  --    --    --    --    --    --    --                    C-6  --    --    --    --    --    --    --    Izod impact               23° C. (V notched)                         1,000 700   720   460   650   1,200 187    strength  -10° C. (No notch)                         >2,000                               >2,000                                     >2,000                                           >2,000                                                 >2,000                                                       >2,000                                                             670    (J/m)     -30° C. (No notch)                         >2,000                               >2,000                                     >2,000                                           870   1,240 >2,000                                                             340    DuPont type               23° C.                         10.3  10.0  10.3  9.8   10.3  11.8  8.8    falling weight              -10° C.                         5.9   5.9   5.9   5.9   5.9   6.6   4.4    impact strength (J)              -30° C.                         4.9   4.9   4.9   4.9   4.9   5.1   4.9    Weathering resistance (ΔE)                         4˜6                               4˜6                                     4˜7                                           5˜6                                                 5˜7                                                       5˜7                                                              9˜11    (Weather meter: 1000 hours)    __________________________________________________________________________                         Comparative Example    Example No.          9     10    11    12    13    14    15    __________________________________________________________________________    Vinyl     Vinyl chloride type                         100    90    85    80    90    85    80    chloride  resin (parts)    type resin              Graft C-1  --    --    --    --    --    --    --    composition              copolymer                    C-2  --    --    --    --    --    --    --              (parts)                    C-3  --    --    --    --    --    --    --                    C-4  --    --    --    --    --    --    --                    C-5  --     10    15    20   --    --    --                    C-6  --    --    --    --     10    15    20    Izod impact               23° C. (V notched)                          40   370   660   160   560   650   750    strength  -10° C. (No notch)                          30   1,290 >2,000                                           570   >2,000                                                       >2,000                                                             >2,000    (J/m)     -30° C. (No notch)                         --    680   1,200 300   1,020 1,250 >2,000    DuPont type               23° C.                          0.44 6.6   6.9   6.9   8.8   9.8   10.3    falling weight              -10° C.                          0.15 2.0   4.4   4.4   4.9   5.1   5.1    impact strength (J)              -30° C.                         --    1.5   2.5   2.9   2.9   2.9   2.5    Weathering resistance (ΔE)                         >30    8˜10                                      8˜10                                            8˜10                                                 >30   >30   >30    (Weather meter: 1000 hours)    __________________________________________________________________________

EXAMPLE 31 (1) Production of Graft Rubber Polymer Latex (A)

In a 4-liter reactor equipped with a stirrer, the following butadienerubber latex 1, emulsifier 2 and butyl acrylate (containing 2% ofcrosslinking agent) 3 were placed and mixed uniformly to give anemulsion. After making the dissolved oxygen content in the emulsion 2ppm or less by introducing nitrogen thereinto for about 1.5 hours, thefollowing polymerization initiator 4 and auxiliary 5 were added thereto.The temperature was raised to 60° C. and the polymerization was carriedout for about 2 hours at 60° C. to give a graft rubber copolymer latex(A) with a conversion of 75%.

    ______________________________________    Component 1               Butadiene rubber latex                                   1324 g               (UB-1001S, mfd. by Nippon               Zeon Co., Ltd., solid               content 34%)    Component 2               Semi-hardened tallow fatty acid                                   11.6 g               potassium salt (KS Soap, mfd.               by Kao Corp.)               Pure water          1060 g    Component 3               Butyl acrylate      1050 g               Triallyl isocyanurate                                   20 g    Component 4               Potassium persulfate                                   0.5 g               Pure water          50 g    Component 5               Sodium sulfite      0.13 g               Pure water          50 g    ______________________________________

(2) Production of Impact Modifier Graft Copolymer (C)

In a 4-liter flask equipped with stirrer, the following graft rubberpolymer latex 1 obtained in above (1) (solid content 42%, containingunreacted polymerizable monomers), emulsifier 2 and graft component 3were placed and mixed uniformly to give an emulsion. After making thedissolved oxygen content in the emulsion 2 ppm or less by introducingnitrogen thereinto, the following initiator auxiliary 4 was addedthereto and the temperature was raised to 65° C. After about 1.5 hoursfrom the time reaching 65° C., the following component 5 was added, andthen a uniformly emulsified mixture of the components 6 and 7 was addeddropwise in about 1.5 hours. After completion of the dropwise addition,stirring was continued for further 3 hours. Then, the followingcomponent 8 was added thereto and the polymerization was carried out for1 hour at 75° C. to give a graft copolymer latex with a conversion of97% or more and substantially completed in polymerization. After coolingto room temperature, an aqueous solution of polyvinyl alcohol was addedto the graft copolymer latex with stirring for coagulating. Afterrepeating filtering and washing, and subsequent drying, a powder ofimpact modifier (graft copolymer) was obtained.

    ______________________________________    Component 1               Graft rubber polymer latex                                   2332 g    Component 2               Sodium lauryl sulfate                                   1.2 g               Potassium oleate    6.0 g               Pure water          340 g    Component 3               Acrylonitrile       20.2 g               Styrene             40.8 g               Cumene hydroperoxide                                   0.22 g    Component 4               Sodium formaldehyde sulfoxylate                                   1.0 g               Pure water          60 g    Component 5               K.sub.2 CO.sub.3    5.1 g               Pure water          100 g    Component 6               Potassium oleate    4.2 g               Pure water          235 g    Component 7               Acrylonitrile       51.9 g               Styrene             120 g               Cumene hydroperoxide                                   0.6 g               t-Dodecyl mercaptan 0.65 g    Component 8               Potassium persulfate                                   1.2 g               Pure water          100 g    ______________________________________

(3) Polycarbonate resin composition

The obtained impact modifier in an amount 10 parts was compounded with100 parts of polycarbonate resin (Iupilon S-100, mfd. by Mitsubishi GasChemical Co., Inc.), melt kneaded at 250° C. and press molded at 240° C.to give a resin plate of 3 mm thick. Test pieces were cut from the resinplate. The Izod impact strength (notched) was 490 J/m, which values wasvery high compared with the value of 300 J/m when no impact modifier wasadded.

EXAMPLE 32

The impact modifier obtained in Example 31 in an amount of 10 parts wascompounded with 100 parts of poly(methyl methacrylate) (Parapet G-1000,mfd. by Kyowas Gas Chemical Industry Co., Ltd.), melt kneaded at 190°C., and press molded at 200° C. to give a resin plate of 3 mm thick.Test pieces were cut from the resin plate. The Izod impact strength(notched) was 80 J/m, which value was higher than the valve of 30 J/mwhen no impact modifier was added.

EXAMPLE 33

The impact modifier obtained in Example 31 in an amount of 10 parts wascompounded with 100 parts of polypropylene (Hipol J800, mfd. by MitsuiPetrochemical Industries, Ltd.), melt kneaded at 180° C., and pressmolded at 190° C. to give a resin plate of 3 mm thick. Test pieces werecut from the resin plate. The Izod impact strength (notched) was 40 J/m,which value was higher than the value of 20 J/m, when no impact modifierwas added.

EXAMPLE 34

A graft copolymer latex was prepared in the same manner as described inExample 31(2) except for using the following components 1 to 8. Aftercoagulating, filtering, washing and drying, there was obtained a powderof impact modifier.

    ______________________________________    Component 1               Graft rubber polymer latex                                   2571 parts               obtained in Example 31(1)               (solid content 42%)    Component 2               Sodium lauryl sulfate                                   1.2 parts               Potassium oleate    6.0 parts               Deionized water     340 parts    Component 3               Acrylonitrile       10.1 parts               Styrene             20.4 parts               Cumene hydroperoxide                                   0.11 parts    Component 4               Sodium formaldehyde 1.03 parts               sulfoxylate               Deionized water     60 parts    Component 5               Potassium carbonate 5.26 parts               Deionized water     100 parts    Component 6               Potassium oleate    2.1 parts               Deionized water     120 parts    Component 7               Acrylonitrile       26.0 parts               Styrene             60.0 parts               Cumene hydroperoxide                                   0.3 parts               t-Dodecyl mercaptan 0.33 parts    Component 8               Potassium persulfate                                   2.5 parts               Deionized water     100 parts    ______________________________________

The resulting impact modifier in an amount of 8 parts was compoundedwith 100 parts of vinyl chloride homopolymer (TK-1000, mfd. by Shin-EtsuChemical Co., Ltd.), 3 parts of dibutyl tin maleate as a stabilizer, 0.5part of calcium stearate and 0.5 part of stearyl stearate and meltkneaded using a single screw extruder having a diameter of 40 mm (mfd.by Thermoplastic Industry Co., Ltd.) to give pellets. The pellets werecompression molded to give a resin plate of 150 mm wide, 150 mm long and3 mm thick. Test pieces were cut out of the resin plate and subjected tothe following tests with the following results.

    ______________________________________    Izod impact strength (notched)                            1120   J/m    Flexural strength (ASTM D790)                            52     MPa    Flexural modulus (ASTM D790)                            2180   MPa    Vicat softening temperature                            94.5° C.    (JIS K7206)    Melt flow rate (JIS K7210)                            0.39    (200° C., 98N)    ______________________________________

EXAMPLE 35

A graft copolymer latex was prepared in the same manner as described inExample 24 except for using the following graft rubber polymer (A) andthe components (1) to (7). After coagulating, filtering, washing anddrying, there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               The graft rubber polymer latex                                  2037 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.2 parts               Potassium oleate   5.0 parts               Deionized water    240 parts    Component (2)               Acrylonitrile      30.3 parts               Styrene            61.2 parts               Cumene hydroperoxide                                  0.32 parts    Component (3)               Sodium formaldehyde                                  1.63 parts               sulfoxylate               Deionized water    100 parts    Component (4)               Potassium carbonate                                  7.65 parts               Deionized water    120 parts    Component (5)               Potassium oleate   6.3 parts               Deionized water    350 parts    Component (6)               Acrylonitrile      77.8 parts               Styrene            180 parts               Cumene hydroperoxide                                  0.9 parts               t-Dodecyl mercaptan                                  1.0 parts    Component (7)               Potassium persulfate                                  3 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride resin having an average degree ofpolymerization of 650 (Ryuron E650, mfd. by Tosoh Corp.), 3 parts ofdibutyl tin maleate as a stabilizer, 0.5 part of calcium stearate, and0.5 part of stearyl stearate, and melt kneaded using a single screwextruder having a diameter of 40 mm (mfd. by Thermoplastic Industry Co.,Ltd.) to give pellets. The pellets were compression molded to give aresin plate of 150 mm wide, 150 mm long and 3 mm thick. Test pieces werecut from the resin plate and subjected to the following tests in thesame manner as described in Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            400    J/m    Flexural strength       58     MPa    Vicat softening temperature                            81.9° C.    ______________________________________

EXAMPLE 36

A graft copolymer latex was obtained in the same manner as described inExample 24 except for using the following graft rubber copolymer (A) andthe components (1) to (7). After coagulating, filtering, washing anddrying, there was obtained an impact modifier.

    ______________________________________    Graft rubber copolymer (A):    ______________________________________               Graft rubber polymer latex                                  1730 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.02 parts               Potassium oleate   5.1 parts               Deionized water    200 parts    Component (2)               Acrylonitrile      25.7 parts               Styrene            52 parts               Cumene hydroperoxide                                  0.27 parts    Component (3)               Sodium folmaldehyde                                  1.4 parts               sulfoxylate               Deionized water    100 parts    Component (4)               Potassium carbonate                                  6.5 parts               Deionized water    150 parts    Component (5)               Potassium oleate   5.34 parts               Deionized water    300 parts    Component (6)               Acrylonitrile      66.1 parts               Styrene            66.1 parts               α-Methyl styrene                                  86.8 parts               Cumene hydroperoxide                                  3.3 parts               t-Dodecyl mercaptan                                  0.85 parts    Component (7)               Potassium persulfate                                  3 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride resin (Ryuron E650, mfd. by TosohCorp.), 3 parts of dibutyl tin maleate as a stabilizer, 0.5 parts ofcalcium stearate and 0.5 part of stearyl stearate and melt kneaded usinga single screw extruder having a diameter of 40 mm (mfd. byThermoplastic Industry Co., Ltd.) to give pellets. The pellets werecompression molded to give a resin plate of 150 mm wide, 150 mm long and3 mm thick. Test pieces were cut out of the resin plate and subjected tothe tests in the same manner as described in Example 34 with thefollowing results.

    ______________________________________    Izod impact strength (notched)                            370    J/m    Flexural strength       58     MPa    Flexural modulus        2200   MPa    Vicat softening temperature                            80.1° C.    Melt flow rate (190° C., 98N)                            3.3    ______________________________________

EXAMPLE 37

A graft copolymer latex was obtained in the same manner as described inExample 24 except for using the following graft rubber polymer (A) andthe components (1) to (7). After coagulating, filtering, washing anddrying, there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               Graft rubber polymer latex                                  1632 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.0 parts               Potassium oleate   4.2 parts               Deionized water    200 parts    Component (2)               Acrylonitrile      14.1 parts               Methyl methacrylate                                  28.6 parts               Cumene hydroperoxide                                  0.15 parts    Component (3)               Sodium formaldehyde                                  0.7 parts               sulfoxylate               Deionized water    50 parts    Component (4)               Potassium carbonate                                  3.6 parts               Deionized water    100 parts    Component (5)               Potassium oleate   3.0 parts               Deionized water    160 parts    Component (6)               Acrylonitrile      36.4 parts               Methyl methacrylate                                  84.0 parts               Cumene hydroperoxide                                  0.42 parts               t-Dodecyl mercaptane                                  0.46 parts    Component (7)               Potassium persulfate                                  3.0 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride-ethylene copolymer having an averagedegree of polymerization of 650 (Ryuron E-650, mfd. by Tosoh Corp.), 3parts of dibutyl tin maleate as a stabilizer, 0.5 parts of calciumstearate and 0.5 part of stearyl stearate, and melt kneaded using asingle screw extruder having a diameter of 40 mm (mfd. by ThermoplasticIndustry Co., Ltd.) to give pellets. The pellets were compression moldedto give a resin plate of 150 mm wide, 150 mm long and 3 mm thick. Testpieces were cut out of the resin plate and subjected to the tests in thesame manner as described in Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            600    J/m    Flexural strength       56     MPa    Flexural modulus        2100   MPa    Vicat softening temperature                            80.3° C.    Melt flow rate (190° C., 98N)                            2.8    ______________________________________

EXAMPLE 38

A graft copolymer latex was prepared in the same manner as described inExample 24 except for using the following graft rubber copolymer (A) andthe components (1) to (7). After coagulating, filtering, washing anddrying, there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               Graft rubber polymer latex                                  2332 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.2 parts               Potassium oleate   6.0 parts               Deionized water    340 parts    Component (2)               Methyl methacrylate                                  61.0 parts               Cumene hydroperoxide                                  0.22 parts    Component (3)               Sodium formaldehyde               sulfoxylate        1.0 part.sup.               Deionized water    60 parts    Component (4)               Potassium carbonate                                  5.1 parts               Deionized water    100 parts    Component (5)               Potassium oleate   4.2 parts               Deionized water    235 parts    Component (6)               Methyl methacrylate                                  171.9 parts               Cumene hydroperoxide                                  0.6 parts               t-Dodecyl mercaptan                                  0.65 parts    Component (7)               Potassium persulfate                                  1.2 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride-ethylene copolymer having an averagedegree of polymerization of 650 (Ryuron E-650, mfd. by Tosoh Corp.), 3parts of dibutyl tin maleate as a stabilizer, 0.5 parts of calciumstearate and 0.5 part of stearyl stearate, and melt kneaded using asingle screw extruder having a diameter of 40 mm (mfd. by ThermoplasticIndustry Co., Ltd.) to give pellets. The pellets were compression moldedto give a resin plate of 150 mm wide, 150 mm long and 3 mm thick. Testpieces were cut out of the resin plate and subjected to the tests in thesame manner as described in Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            380    J/m    Flexural strength       57     MPa    Flexural modulus        2110   MPa    Vicat softening temperature                            81.2° C.    Melt flow rate (190° C., 98N)                            4.6    ______________________________________

EXAMPLE 39

A graft copolymer latex was prepared in the same manner as described inExample 24 except for using the following graft rubber polymer (A) andthe components (1) to (7). After coagulating, filtering, washing anddrying, there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               Graft rubber polymer latex                                  2332 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.2 parts               Potassium oleate   6.0 parts               Deionized water    340 parts    Component (2)               Styrene            61.0 parts               Cumene hydroperoxide                                  0.22 parts    Component (3)               Sodium formaldehyde                                  1.0 parts               sulfoxylate               Deionized water    60 parts    Component (4)               Potassium carbonate                                  5.1 parts               Deionized water    100 parts    Component (5)               Potassium oleate   4.2 parts               Deionized water    235 parts    Component (6)               Styrene            55.4 parts               Methyl methacrylate                                  0.6 parts               t-Dodecyl mercaptan                                  0.65 parts    Component (7)               Potassium persulfate                                  1.2 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride resin having an average degree ofpolymerization of 650 (Ryuron E-650, mfd. by Tosoh Corp.), 3 parts ofdibutyl tin maleate, 0.5 part of calcium stearate and 0.5 part ofstearyl stearate, and melt kneaded using a single screw extruder havinga diameter of 40 mm (mfd. by Thermoplastic Industry Co., Ltd.) to givepellets. The pellets were compression molded to give a resin plate of150 mm wide, 150 mm long and 3 mm thick. Test pieces were cut out of theresin plate and subjected to the tests in the same manner as describedin Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            430    J/m    Flexural strength       56     MPa    Flexural modulus        2100   MPa    Vicat softening temperature                            80.5° C.    Melt flow rate (190° C., 98N)                            3.3    ______________________________________

EXAMPLE 40

A graft copolymer latex was prepared in the same manner as described inExample 24 except for using the following graft rubber polymer (A) andcomponents (1) to (7). After coagulating, filtering, washing and drying,there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               Graft rubber polymer (A)                                  1748 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.2 parts               Potassium oleate   6.0 parts               Deionized water    340 parts    Component (2)               Acrylonitrile      40.4 parts               Styrene            81.6 parts               Cumene hydroperoxide                                  0.43 parts    Component (3)               Sodium formaldehyde                                  1.63 parts               sulfoxylate               Deionized water    100 parts    Component (4)               Potassium carbonate                                  10.2 parts               Deionized water    170 parts    Component (5)               Potassium oleate   8.3 parts               Deionized water    470 parts    Component (6)               Acrylonitrile      103.7 parts               Styrene            240.1 parts               Cumene hydroperoxide                                  1.2 parts               t-Dodecyl mercaptan                                  1.31 parts    Component (7)               Potassium persulfate                                  1.2 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride resin having an average degree ofpolymerization of 650 (Ryuron E-650, mfd. by Tosoh Corp.), 3 parts ofdibutyl tin maleate as a stabilizer, 0.5 part of calcium stearate, and0.5 part of stearyl stearate, and melt kneaded using a single screwextruder having a diameter of 40 mm (mfd. by Thermoplastic Industry Co.,Ltd.) to give pellets. The pellets were compression molded to give aresin plate of 150 mm wide, 150 mm long and 3 mm thick. Test pieces werecut from the resin plate and subjected to the tests in the same manneras described in Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            200    J/m    Flexural strength       60     MPa    Flexural modulus        2100   MPa    Vicat softening temperature                            81.9° C.    Melt flow rate (190° C., 98N)                            3.4    ______________________________________

COMPARATIVE EXAMPLE 16

A graft copolymer latex was obtained in the same manner as described inExample 24 except for using the following graft rubber copolymer (A) andcomponents (1) to (7). After coagulating, filtering, washing and drying,there was obtained a powder of impact modifier.

    ______________________________________    Graft rubber polymer (A):    ______________________________________               Graft rubber polymer latex                                  1500 parts               obtained in Example 24(1)               (solid content: 40%)    Component (1)               Sodium lauryl sulfate                                  1.2 parts               Potassium oleate   6.0 parts               Deionized water    340 parts    Component (2)               Acrylonitrile      50.5 parts               Styrene            102 parts               Cumene hydroperoxide                                  0.55 parts    Component (3)               Sodium formaldehyde                                  1.03 parts               sulfoxylate               Deionized water    60 parts    Component (4)               Potassium carbonate                                  5.26 parts               Deionized water    100 parts    Component (5)               Potassium oleate   10.5 parts               Deionized water    588 parts    Component (6)               Acrylonitrile      129.8 parts               Styrene            300 parts               Cumene hydroperoxide                                  1.5 parts               t-Dodecyl mercaptan                                  1.63 parts    Component (7)               Potassium persulfate                                  2.5 parts               Deionized water    100 parts    ______________________________________

The obtained impact modifier in an amount of 10 parts was compoundedwith 90 parts of vinyl chloride resin having an average degree ofpolymerization of 650 (Ryuron E650, mfd. by Tosoh Corp.), 3 parts ofdibutyl tin maleate as a stabilizer, 0.5 part of calcium stearate and0.5 part of stearyl stearate, and melt kneaded using a single screwextruder having a diameter of 40 mm (mfd. by Thermoplastic Industry Co.,Ltd.) to give pellets. The pellets were compression molded to give aresin plate of 150 mm wide, 150 mm long and 3 mm thick. Test pieces werecut from the resin plate and subjected to the tests in the same manneras described in Example 34 with the following results.

    ______________________________________    Izod impact strength (notched)                            80     J/m    Flexural strength       60     MPa    Flexural modulus        2200   MPa    Vicat softening temperature                            82.0° C.    Melt flow rate (190° C., 98N)                            3.5    ______________________________________

EXAMPLES 41 TO 43, COMPARATIVE EXAMPLE 17

The impact modifier obtained in Example 31 in amounts as listed in Table5 was compounded with 100 parts of vinyl chloride resin having anaverage degree of polymerization of 800 (TK-800, mfd. by Shin-EtsuChemical Co., ltd.), 3 parts of dibutyl tin maleate as a stabilizer, 1part of polyethylene wax and 0.5 part of calcium stearate, melt kneadedat 170° C., and press molded at 190° C. to give a resin plate. Testpieces were cut out of the resin plate and subjected to the tests in thesame manner as described in Example 34. The results are shown in Table5.

                  TABLE 5    ______________________________________             Compara-             tive             Example Example    Example No.               17        41       42      43    ______________________________________    Amount of impact               0         6        8       10    modifier (parts)    Izod impact               62        400      860     980    strength (J/m)    Tensile strength               55        48       45      42    (MPa)    Flexural modulus               2820      2300     2270    2240    (MPa)    Vicat softening               92.4      91.5     91.5    91.0    temperature (°C.)    ______________________________________

EXAMPLES 44 TO 46, COMPARATIVE EXAMPLE 18

The impact modifier obtained in Example 31 in an amount of as listed inTable 6 was compounded with 100 parts of vinyl chloride resin having anaverage degree of polymerization of 1050 (TK-1000, mfd. by Shin-EtsuChemical Co., Ltd.), 1 part of tribasic lead sulfate, 0.5 part ofdibasic lead stearate, 2 parts of lead stearate, 0.3 part of bariumstearate, and 0.2 part of calcium stearate, melt kneaded at 170° C. andpress molded at 190° C. to give a resin plate. Test pieces were cut outof the resin plate and subjected to the tests in the same manner asdescribed in Example 34. The results are shown in Table 6.

                  TABLE 6    ______________________________________             Compara-             tive             Example Example    Example No.               18        44       45      46    ______________________________________    Amount of impact               0         6        8       10    modifier (parts)    Izod impact               86        450      1090    1250    strength (J/m)    Tensile strength               54        50       46      45    (MPa)    Flexural modulus               2730      2300     2220    2230    (MPa)    Vicat softening               96.8      95.5     95.2    94.4    temperature (°C.)    ______________________________________

EXAMPLE 47

The impact modifier obtained in Example 31 in an amount of 9 parts wascompounded with vinyl chloride-ethylene copolymer having an averagedegree of polymerization of 650 (ethylene content 4% or less, RyuronE650, mfd. by Tosoh Corp.), 3 parts of dibutyl tin maleate as astabilizer, 1 part of calcium stearate, and 0.5 part of stearylstearate, and melt kneaded at 150° to 180° C. using a full-flight singlescrew extruder having a diameter of 40 mm (mfd. by ThermoplasticIndustry Co., Ltd.) to give pellets. The pellets were press molded at185° to 195° C. to give a resin plate. Test pieces were cut out of theresin plate and subjected to the Izod impact test. The Izod impactstrength (notched) was 870 J/m.

COMPARATIVE EXAMPLE 19 (1) Production of Graft Rubber Polymer

A graft rubber polymer was prepared using the same apparatus and thesame components as used in Example 31(1). After 30 minutes from the timereached 60° C., the reaction system was cooled to give a graft rubberpolymer latex with a conversion of 46%.

(2) Production of Graft Copolymer (C)

A graft copolymer powder was produced in the same manner as described inExample 31(2) except for using the graft rubber polymer obtained inabove (1) in the same amount as in Example 31 as the graft rubberpolymer latex 1.

(3) Production of Vinyl Chloride Type Resin Composition

A vinyl chloride type resin composition was prepared in the same manneras described in Example 47 except for using 9 parts of the powder ofgraft copolymer (C) obtained in above (2). Test pieces were prepared andsubjected to the test in the same manner as described in Example 47.

The Izod impact strength (notched) was 400 J/m, which value was lowerthan that obtained in Example 47.

EXAMPLE 48 (1) Production of Graft Rubber Polymer Latex

The polymerization was carried out using the same apparatus and the samecomponents as used in Example 31(1). After about 2 hours from the timereaching 60° C., 0.5 g of potassium persulfate dissolved in 50 g ofdeionized water was added thereto. The polymerization was carried out at60° C. for further 3 hours to give a graft rubber polymer latex (A) witha conversion of 98% or more and substantially completed inpolymerization.

(2) Production of Graft Copolymer (C)

A powder of graft copolymer was produced in the same manner as describedin Example 31(2) except for using the latex produced in above (1) in thesame amount as in Example 31 as the graft rubber polymer latex 1.

(3) Production of Vinyl Chloride type Resin Composition

The graft copolymer powder obtained in above (2) in an amount 9 partswas mixed with 100 parts of vinyl chloride-ethylene copolymer having anaverage degree of polymerization of 650 (Ryuron E650, mfd. by TosohCorp.) to produce a vinyl chloride type resin composition in the samemanner as described in Example 47. Test pieces were obtained from thevinyl chloride type resin composition and subjected to the test in thesame manner as described in Example 47. The Izod impact strength(notched) was 550 J/m, which value was lower than that of Example 47 buthigher than that of Comparative Example 19.

As mentioned above, the impact modifiers of the present invention canimpart particularly excellent impact resistance (Izod impact strength,Du Pont type falling weight impact test) and weathering resistance tothermoplastic resins without losing excellent inherent properties of theresins.

Thus, the thermoplastic resin compositions of the present invention canbe used in various electric appliances, house-building parts andmaterials for outdoor or indoor uses, molded articles of furniture, andthe like.

What is claimed is:
 1. An impact modifier of a graft copolymer (C)obtained by (i) emulsion polymerizing(a) 99 to 20 parts by weight of apolymerizable monomer mixture comprising (I) 0.1 to 20% by weight of apolyfunctional monomer, (II) 50 to 99.9% by weight of an acrylic acidalkyl ester, the alkyl moiety thereof having 1 to 13 carbon atoms, and(III) 0 to 30% by weight of a copolymerizable vinyl compound other thanthose mentioned above, in the presence of (b) 1 to 80 parts by weight ofa conjugated diene rubber, a total of the components (a) and (b) being100 parts by weight, to a conversion of 50 to 93% by weight to give agraft rubber polymer (A) containing unreacted polymerizable monomers,and (ii) polymerizing (B) 40 parts by weight or less and more than 0part by weight of one or more monomers comprising (IV) 0 to 100% byweight of an acrylic acid alkyl ester having an alkyl moiety of 1 to 13carbon atoms, (V) 0 to 100% by weight of styrene or substituted styrene,(VI) 0 to 100% by weight of a methacrylic acid alkyl ester, and (VII) 0to 40% by weight of a vinyl cyanide compound, in the presence of 60parts by weight or more and less than 100 parts by weight of the graftrubber polymer (A), a total of the monomers (B) and the graft rubberpolymer (A) being 100 parts by weight.
 2. An impact modifier accordingto claim 1, wherein the amount of the graft rubber polymer (A) is 60 to99% by weight, and the amount of the monomers (B) is 40 to 1% by weight.3. An impact modifier according to claim 1, wherein the monomers (B) inamounts of 5 to 30% by weight are polymerized in the presence of thegraft rubber polymer (A), followed by polymerization of the rest of themonomers (B), each of the monomers (B) separately added comprising(IV) 0to 100% by weight of an acrylic acid alkyl ester having an alkyl moietyof 1 to 13 carbon atoms, (V) 0 to 100% by weight of styrene orsubstituted styrene, (VI) 0 to 100% by weight of a methacrylic acidalkyl ester, and (VII) 0 to 40% by weight of a vinyl cyanide compound.4. An impact modifier according to claim 1, wherein the graft rubberpolymer (A) is obtained by emulsion polymerization of 95 to 55 parts byweight of the polymerizable monomers (a) in the presence of 5 to 45parts by weight of the conjugated diene rubber (b), the total being 100parts by weight.
 5. An impact modifier according to claim 1, wherein thegraft rubber polymer (A) is obtained by emulsion polymerization of 80 to55 parts by weight of the polymerizable monomers (a) in the presence of20 to 45 parts by weight of the conjugated diene rubber (b), the totalbeing 100 parts by weight.
 6. An impact modifier according to claim 1,wherein the polyfunctional monomer (I) is at least one member selectedfrom the group consisting of triallyl isocyanurate, triallyl cyanurate,dicyclopentadiene acrylate and dicyclopentadiene methacrylate.